Comparative Studies On Differences Of Resistance Under Stress Between Liangyoupeijiu And Wuyunjing No.7

This thesis included three parts. In this paper, the seedlings of liangyoupeijiu and wuyunjing No.7 were used as experimental materials. The differences of resistance were studied under stress between liangyoupeijiu and wuyunjing No.7. In the first part, the effects of exogenous sorbitol on liangyoupeijiu and wuyunjing No.7 seedlings under salt stress were studied. Results showed that germination rate of 50 seeds, stem length and root length of 50 seedlings in liangyoupeijiu were higher than wuyunjing No.7; with the increasing of the concentration of salt stress, the content of chlorophyll, electron transport activity of PS II , the O2 evolution of chloroplast, photosynthetic rate and the content of soluble protein decreased, absorption spectrum and fluorescence emission spectrum at room temperature, the ATP content in chloroplast, ATPase activity of chloroplast and activities of SOD, CAT first increased and then decreased, but electron transport activity of PS I , respiration rate, activity of POD , content of soluble sugar and proline and permeability of cell membrane increased. After dealing of salt stress, there were not obviously differences on the polypeptide compositions of thylakoid membrane, but changes of content of soluble protein in 26KD, 45KD had taken place. The resistance to salt stress in liangyoupeijiu is obviously stronger than wuyunjing No.7 and liangyoupeijiu has more significant advantage in output than wuyunjing No.7. Exogenous sorbitol to salt stress has some functions of mitigative effect.In the second part, the differences of resistance to Hg2+ stress in liangyoupeijiu and wuyunjing No.7 were studied. The results showed that with the increasing of the concentration of Hg2+ , content of chlorophyll and electron transport activity of PS I , PS II decreased, but the content of soluble sugar and proline and permeability of cell membrane increased. Absorption spectrum at room temperature , activity of SOD, CAT in liangyoupeijiu and activity of SOD, POD , CAT in wuyunjing No.7 increasedfirst and decreased afterwards, but activity of POD in liangyoupeijiu increased. The resistance to Hg2+ pollution in liangyoupeijiu is obviously stronger than wuyunjing No.7.In the third part, the effects of exogenous 6-BA on liangyoupeijiu and wuyunjing No.7 seedlings under stress of magnesium deficiency were studied. The results showed that with the increasing of magnesium deficiency, the content of chlorophyll and soluble protein decreased, activities of SOD, POD and CAT increased first and decreased afterwards, but activities of NR, the content of soluble sugar and permeability of cell membrane increased. Exogenous 6-BA to the stress of magnesium deficiency has some functions of mitigative effect. The resistance to stress of magnesium deficiency in liangyoupeijiu is obviously stronger than wuyunjing No.7.